Yet another idea for perma death

Basically you have characters who never die, as per usual. But you can make one which you can toggle to perma death.

What leveling the perma death character does is unlock certain stat bonuses/rewards which are either A: Small and can only be gotten from leveling a perma death character or B: Larger and either you unlock them by leveling a perma death character, or you can spend gold to temporarily aquire the bonus for a few hours.